Apparatus for feeding fibre



Dec. 13, 1960 Filed July 28, 1958 J. D. PENNINGTON APPARATUS FOR FEEDING FIBRE 2 Sheets-Sheet 1 Dec. 13, 1960 J. D. PENNINGTON APPARATUS FOR FEEDING FIBRE 2 Sheets-Sheet 2 Filed July 28', 1958 In en 0" .7814! am: #52616 2 APPARATUS FOR FEEDING FIBRE John D. Pennington, Bolton, England, assignor to J. W. Roberts Limited, Yorkshire, England Filed July 28, 1958, Ser. No. 751,477

Claims priority, application Great Britain July 26, 1957 2 Claims. (Cl. 239-77 This invention relates broadly to apparatus for feeding fibre at a uniform rate.

'The feeding offibre at-a regular rate with ability to stop the flow and restart it as desired presents a very difiicult problem. This problem is particularly acute when the fibre is asbestor because of the tendency of asbestor fibres to cling together and to form bridges over the outlet of any container in which the asbestor is put.

Now in the formation of coatings on walls and other surfaces by spraying asbestos, it is necessary to feed the asbestor at a more or less uniform rate to a machine which opens it out and forms it into a suspension to be carried to a spray gun. Whenever the operator of the gun stops spraying, the feed of asbestos into the machine must also be stopped. Hitherto the asbestos has been fed to the machine manually, with the result that two operators have been required.

An object of the invention is to provide an improved machine for use particularly in spraying asbestos.

Another object is to provide a small machine capable of use by a singleoperator.

In an apparatus according to this invention there is a hopper for fibre with a bottom opening, a device at or inside the bottom of the hopper for permitting fibre to leave the hopper at a controlled rate, a rotary disc arranged below the hopper about a vertical axis to receive the fibre and fling it centrifugally outwards to form a suspension in air, a casing around the rotary disc, and a fan having its suction side in, or in communication with, the casing to draw the suspension in and deliver it through a hose.

The invention will be better understood from the following description of the preferred apparatus according to the invention, which is shown in the annexed drawings, in which:

Figure l is a part-sectional elevation of the apparatus;

Figure 2 is an elevation of a bent metal plate used in the apparatus;

Figure 3 is an elevation taken on the line B-B in Figure 1; and

Figure 4 is a plan view of a rotary disc used in the apparatus.

In Figure 1, a hopper 1 for asbestor fibre has a circular cross-section and tapering sides that are wider at the bottom than at the top, This construction helps to reduce any tendency of fibre within the hopper to bridge between the walls of the hopper or to stick to them. At its lower end the hopper fits loosely inside a cylindrical casing 2. Bolts 3 pass through holes 4 in the wall of the casing 2, through corresponding holes 5 in the wall of the hopper 1 and also through pads 6 secured to the hopper wall. Hopper 1 and casing 2 are thereby held together. U slots 7 in the bottom rim of the hopper fit over a diametrical shaft 8 running in bearing blocks 9 and 10. A handle 11 is fitted onto one end of the shaft 8 where this projects outside both the hopper 1 and the casing 2.

2,964,244 Patented Dec. 13, 1960 A bent metal plate 12 comprises two semicircular halves 13 and 14 which meet along a line 15. When viewed in elevation as in Figure 2, the plate has the shape of an inverted and shallow V. The plate is brazed along the line 15 to a collar 16. The collar fits the shaft 8, and is secured to it by a set screw 17. A metal loop 18 is welded at each end to the line 15 on the uppermost face of the plate 12, and lies in the plane of the bisector of the angle between the two halves 13 and 14.

When the loop 18 points vertically upwards and the hopper 1 is full of fibre, the clearance between the edges of the plate 12 and the walls of the hopper 1 is such that gravity is unable to force the fibre past the plate and so out of the hopper. However, an operator can rotate the handle 11 to and fro, thereby causing the plate to rock. Such rocking opens larger gaps between the plate and the hopper 1 and so allows fibre to escape, the loop 18 serving to disturb the fibre immediately above the plate and thereby to induce it to fall when the plate 12 rocks to enable it to do so. The handle 11 is fixed rigidly to an end plate 19 and this end plate is keyed to the shaft 8. A pin 20 projects from the end plate 19. This pin fouls adjustable stop-screws 21 set in a stop mounting 22 that is integral with the bearing block 10 supporting the handle end of the shaft'8. The shaft 8 is therefore prevented from rotating through more than a limited arc.

Beneath the plate 13 a disc 23 is mounted to rotate in a horizontal plane on a spindle 24 that lies along the axis of the casing 2. A fan impellor 25 is also mounted on this spindle, which is rotated by an electric motor 26. The disc 23 is slightly conical and two parallel vanes 27 are mounted on its upper surface, each vane projecting tangentially from a central circular boss 28 and terminating at the circumference of the disc, as is shown most clearly in Figure 4. The inner walls 29 of the casing 2 are conical in the vicinity of the disc 23, and there is only a small annular gap 30 between them and the edge of the disc. If the apparatus is used to supply asbestos fibres this gap is preferably of the order of A Air enters the apparatus through the gap between the hopper and the casing, and this air is attracted by the fan, thereby creating a downdraught in the lower part of the casing.

Fibre falling into the casing 2 from the hopper 1 drops onto the upper surface of the disc 23, either directly, or after bouncing off the sloping inner walls 29 of the easing. The vanes 27 of the revolving disc 23 break up any lumps of fibre that drop onto the disc, and centrifugal force throws fibre from the surface of the disc to the periphery of it as a fluid suspension in air. This suspension tends to revolve slowly above the gap 30 until it is sucked through by the fan 25. Once through the gap, the fibre is sucked into the fan 25 and leaves the casing through an outlet port 31, whence it leaves the apparatus as a suspension of fibre in air, and then travels through a hose 32 to a spray device 33. This device is worked electrically, being run off the same motor 26 as the rest of the apparatus. The handle 11 is hollow, and inside it is a switch mechanism that is connected to the spray device 33 by a lead 34 and that switches on the device 33 whenever the handle 11 is rocked.

The rate of fibre discharge is controlled by varying the rate of oscillation of the plate, or the amplitude of the movement. The latter may conveniently be done by adjustment of the stop-screws 21.

Apparatus according to the invention may be used for feeding various fibres in addition to asbestor, e.g. slag or rock wool or textile fibres, and it may feed any of the fibres to conveyor belts, oscillating conveyors or directly into other machines where the fibre is processed.

I' claim:

1. A machine of thekindbywhich asbestos or other mineral fibres are formed into a suspension and sprayed on to a surface comprising, in combination, a hopped for the fibre with a bottom opening and sides tapering in such a direction as-to give the widest opening at the bottom of said hopper; a-. fibre agitating and rate controlling device at the bottom of the hopper for both agitating the fibre within the hopper and permitting it to leave the hopper at a controlled rate, a rotary disc arranged below the hopper about a vertical axistoreceive the fibre and fling it centrifugally outwards to form: a suspension in air, a casing vented to atmosphere around said rotary disc and separated from it by a narrow anmineralfibres are formed into a suspensionandsprayed. 20 2,550,354

4., on to a surface comprising, in combination, a hopper for the fibre with a bottom opening, an oscillating plate at the bottom of the hopper for both agitating the fibre within the hopper and permitting it to leave the hopper at a controlled rate, a rotary disc arranged below the hopper about a vertical axis to receive the fibre and fling it centrifugally outwards to 'form a suspension in air, a

casing ventedv to atmosphere around-said rotary disc and spray device at the delivery end of the hose, the spray device and the, oscillating plate; bei'ng interlinked so that the spray device is operative when the plate oscillates and is inoperative when the plate is still.

References Cited in the file of this patent UNITED STATES PATENTS Jacobsen Apr.,24,, 1951 

